Ignition system for flares, bombs, and the like adapted to be dropped from aircraft



Oct. 14, 1924. O 1,511,622

O. IGNITION SYSTEM FOR FLARES, BOMBS, AND THE LIKE, ADAPTED TO BEDROPPED FROM AIRCRAFT Filed Oct. 30. 1923 3 Sheets-Sheet 1 Oct. 14 1924-LUCAS 2 y E a B h o 4 s m m M S D 3 A E K .1 mu RS Gl mm. A M3 m. t Fc D0 P 0 PM 0. BMF

IGNITION SYSTEM FOR FLARES, BOMBS,

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0. D LUCAS IGNITION SYSTEM FOR FLARES, BOMBS, AND THE LIKE, ADAPTED TOBE DROPPED FROM AIRCRAFT Filed Oct. 30. 1923 3 Sheets-Sheet 5 PatentedOct. 14, 1924.-

UNITED STATES PATENT OFFICE.

IGNITION SYSTEM FO'R FIi ARES, BONDS, AND THE LIKE ADAPTED TO BE DROPPE)ownn DAVID LUCAS, or BAYSWATER, LONDON, ENGLAND, assrenon. we wannaLIMITED, or wns'rmsrnn, LONDON,

ENGLAND, A BRITISH COMPANY.

FROM AIRCRAFT.

Application filed October 30, 1923. Serial No. 671,876.

To all whom it may concern:

Be it known that I, OWEN DAVID LUCAS, a

subject of the King of Great Britain, residing at 49 Linden Gardens,Bayswater, in the county of London, England, have invented certain newand useful Improvements in Ignition Systems for Flares, Bombs, and thelike Adapted to be Dropped from Aircraft, of which the following is aspecification.

This invention relates to an electrical sys tem for the ignition offlares, bombs and other explosive or ignitible bodies adapted to bedropped from air craft and has for its chief object to ensure eflicientignition. electrically after the body has been dropped and topreventrisk of premature ignition, that is, ignition before t e body hascleared the rack or release mechanism of the aircraft. The body to bedropped will, for convenience, usually be referred to hereinafter as abomb, but it is to be understood that this term is-meaLntto cover anytype of fuzed body which is to be ignited after dro ping. According tothis invention the uze is provided with timing or delay mechanismadapted to be ignited electrically by an electrical ignition devicecontrolled by current supplied through a circuit associated with releasemechanism on the aircraft, at the time of release. In the constructionof fuze preferreda head adapted to be engaged by type a springcontrolled gripping electrical switch device is provided with a pair ofinsulated contacts connected to the ignition device, such as a bridgewire in the fuze primer, The head is referably mounted to swivel in theend oft e fuze. I

The electrical release mechanism on the aircraft supplying the fuzecurrent as the bomb is released comprises an operating switch associatedwith the usual operating lever and having a safety catch which preventsthe switch closing the firing circuit unless the catch is actuated, sothat on movingover the operating lever without releasing the catch thebomb is dropped without ignition. The electrical release switch whichgrips the fuze head comprises two gripping jaws having contact piecesfor the head and telescopic members attached to the bomb carrier,provided with contacts which are brought together only after the bombhas begun to drop upon its mechanical release, contact being maintainedor an a preciable time by the yielding of the tel scopic device whichallows the ri'ppin jaws to retain their hold until t e bom has droppedthrough a short distance, when the jaws are opened for complete release.

For' a rack carrying more than one bomb a distributor switch is providedcomprising an insulated contact arm travelling with the release bar ofthe rack and adapted to close thecircuit connected to the release switchas the release bar passes over the release point in its travel, so thatcontact is made just before-the release of the bomb.

In order that the said invention may be clearly understood and readilycarried into effect the same will now be described more fully withreference to the accompanying drawings, in which Figure 1 is a sectionalview, and

Figure 2 an elevation of an e ectrically operated fuze embodying thisinvention and suitable for use with flares.

Figure 3 is a sectional view of an adaptor for use with bombs, shownwith the fuze in dotted lines.

Figure 4 is a plan of a safety collar empltiyed in the bomb fuze.

igure 5 is an elevation of the bomb fuze as fitted to an exploder tubeof ordinary Figures 6, and 8 are respectivel a side elevation, alongitudinal section an an elevation in extended position of the releaseswitch.

Figures 9 and 10 are respectively a Ian and a side view of a bomb rackadap for electrical fuze ignition.

Figure 11 is a diagrammatic view of the ignition system associated withthe rack.

Figures 12 and 13 are detail views of a distributor switch on the rack;and

Figures 14 and 15 are respectively a section and an elevation of anoperating switch lever.

Referring first to the construction of fuze illustrated in Figures 1 and2 and adapted for use with flares, the fuze body comprises the mainfixed ring A I (shown with a time scale a marked upon its flange), thebase B which is screwed into the body of the flare,

the upper fixed ring C with channel 0 for the fun c p sition and the capD screwedon td the upper screw threaded part a of the ring A. The boss 6of the base B is screwed into the ring A and carries the fuze primer Ein which is the electrical ignition device, such as a'currentheatedbridge wire connected to the lead 6. F is the contact head comprisingthe two contact. members 1, f separated by the insulating piece f thecontact f being made in one with the stem 3 which passes through the capD and is secured in the cap by the ring f into which it is screwed, thehead F being free to rotate around its axis in the cap D withoutinterfering with the contact mechanism. The contact f is electricallyconnected by the pin f to the insulated centre pin i receivi'ng the endof the spring pressed contact rod f, the lower end of which is pressedby the spring against the pin e connected to the ignition lead e. Theignition circuit is therefore through the contact f, rod f, lead 6 tothe fuze primer and back through the'fuze body to the contact I. Thehead F is adapted to be gripped between contact making gripping jaws ashereinafter described. When ignition is effected at the primer E thecomposition in the ring C is fired through the flash channel a and thisin turn ignites the composition in the adjustable ring Gr situatedbetween the fixed ring C and the flange of the ring A. The

- adjustment of the ring (Jr determines in the usual manner the delayperiod between the ignition of the fuze and the firing of the charge.

Figures 3, 4: and 5 show the application of the method to a bomb fuze tobe fired on impact, the electrically operated fuze serv ing to arm thebomb by removing a safety ring H at the base of the fuze after apredetermined interval from the release of the bomb. The body of thefuze is on the lines already described, the timing ring being used todetermine the moment when the bomb is armed after leaving its carrier asthe object is to arm the bomb after it has safely cleared the aircraft.B is the fixed supporting member which is screwed into the head of theusual exploder tube J of the, bomb and the striker J projects from theend of a member connected to the supporting member B by the shearing pinj.v The safety ring or disc H is-"made in two parts, as shown in Figure4, which can be separated so as to fall away from the fuze for armingpurposes. When the safety ring is in glace as shewn in the drawings, thebase 2 of the electrical fuze is separated from the fixed member Bcarried by the bomb, so that the fuze body and striker J cannot moveforward relatively to the bomb. If, however, the safety ring H isremoved, on the bomb striking the complete fuze body will move forwardby;its inertia, shearing the pin j and allowing the striker J toopdropping of the erate. The safety pin h" is removed after the bomb isloaded into the carrier in the usual way.

Figure 5 shows the fuze of Figure 3 assembled on the exploder tube J ofthe bomb, the part B being screwed into the exploder head so that thestriker J is over the cap of the exploder detonator in the usual way.

The safety ring H isremoved during the bomb by the firing o theelectrical fine. The two sections of the ring H are secured in place onthe bottom of the fuze body by the lugs 7?. extending into correspondingrecesses at opposite sides of the base B and the shearing pins k whichproject through the lugs h and the base B near .the edge, as shownespecially in Figure 4:. Inside the base 13 immediately behind the lugsh are small pistons or plugs b within which are explosive charges 6fired through the flash passages 12 by the fuze at the end of the perioddetermined bythe length of fuze composition. On ignition of the smallexplosive charges 6 during the fall of the bomb the plugs 6 drive outthe ring lugs 71. breaking the shearin two ring sections to e blown awayfrom the base of the fuze. When the ring H is thus removed the bomb isarmed, as on impact the complete fuze with striker is free to moveforward and explode the bomb, which is, of course provided with theusual impact firing means.

Referring to Figures 6, 7 and 8 showing the contact clip and switchconnected for ignition purposes-to the head F of the fuze, K is theswitch body of fibre orother suitable insulating material, provided atone side with the suspension plate is having a number of perforations kany one of which may serve, by means of a detachable pivot pin,-for fromthe bomb rack or support hereinafter described. the arrangement allowingthe clip to be connected to the fuze head at any anpin k and causing thesuspension of the clip the bomb rack or support are connected re- Ispectively to the inushroomhead m and to the contact I at one sideof theclip, a short lead N passing from the other contact Z along the oppositeside of the clip body to the contact ring n on the upper end of thebody.

The sleeve m 'and rod m are telescopic and the sleeve is also free toslide within the clip body, the action of the device being as follows:--When the bomb is released the head F engaged by the contact jaws Lpulls down the jaws along with the sleeve m until the mushroom head mmeets the contact rin a when the electrical circuit is closed an thefuze ignited. Ignition, however, cannot take place before the release ofthe bomb as the circuit is not closed until the bomb has actuallydropped a short distance. To ensure that the circuit shall be closedthrough the fuze for a sufiicient time to provide for certain ignition,after contact has been made b the mushroom head m the contact jaws donot release the fuze head until the latter has .dropped through asubstantially greater distance. To permit of this the leads N, N whichare'attached both to the clip body and to the upper ends of the grippingjaws L are provided with a certain length n of normally slack cable, sothat when the rod m has reached the end of its travel on the head mabutting on the ring n the sleeve m, with the plug M and the grippingjaws, is free to slide to a further distance against the pressure of thespring m and the sleeve and attached parts extend downwardly into theposition shown in Figure 8, when-the lengths n become taut and pull openthe jaws L, if in the meantime the increased tension of the spring m hasnot already caused the jaws to open against the spring Z Referring tothe bomb rack'and electrical ignition mechanism illustrated in Figures 9to 13, the construction of the rack apart from the electrical controlforms no part of the present invention. The rack comprises the frame 0mounted in a known manner in the aircraft and provided with the base 0on which the rack mechanism is mounted. This comprises a sliding releasebar P provided with ratchet teeth p each corresponding to a step in themovement of the bar and an operating lever Q carrying a pawl q adaptedto engage at each forward movement of the lever with a tooth p and todisplace the bar forward to the left of Figure 9 against the spring p adetent pawl 12 preventing return of the bar. The lever Q is operatedfrom the switch lever hereinafter described through the Bowden wireorother connection g R, R are hooks serving to sup ort the bombs or flares(X, X in Figure 11 which are provided with suitable attachments engagingthe hooks. The hooks are held in supporting position by the pivotedcatches r, the first, third and fourth of-which are shown in engagingposition,'while the second has already been released to allow thebomb'to drop. The catches r are released in succession, one at eachforward move-- ment of the bar P, by shoulders formed by means ofrecesses at the side of the bar,

a shoulder, as the bar is displaced towards the left, meeting thecorresponding pivoted catch 1' and pushing it over past the lever arm 1'of the hook R. The shoulders 71 are positioned on the bar so that thecatches are released successively as the bar is slidden from right toleft through successive steps, one for each operation of the lever Q.

Brackets 0", one for each bomb, project at the side of the rack andserve to carry the contact clip device shown in. Figures 6, 7 and 8 bymeans of the pins 0 at their ends. the pin of any bracket being passedthrough any one of the holes is in the perforated plate or web k of theclip body The bomb is, therefore, supported both by the hook R and atthe fuz'e end by the corresponding bracket 0 which, however, does nottake any substantial part of the weight of the bomb until the its hook.I v

The rack illustrated is to carry four bombs or flares X to be releasedin succession and, in order that each fuze shall be ignited upondropping, electrical circuits are arranged as indicated in the diagramFigure 11, a battery S being provided on the aircraft connected at oneole to the succession of leads N belonging to the release switches andat the other pole through the switch T to the distributor U whichcarries a series of four contacts u, one for each fuze, the fourcontacts being connected, respectively, to the leads N of thecorresponding contact clips. detail in Figures 12 and 13 and the circuitthrough successive fuze clips is closed by the contact member p ontherelease bar P. As will be seen from the diagram Figure 11 when thecontact member p meets the first contact u of the distributor U thecircuit is made for the second fuze countin from the left of Figure 9,while the circuits for the successive fuzes are closed at thedistributor as the contact member -12 moves with the release bar P fromright to left, the final contact being made for the left-hand fuzelatter is released from as the final catch r is released by the end ofthe release bar P.

The operating switch lever T is shown separately in Figures 14 and 15and carries the switch arm V with spring 41 and switch member '2) whichnormally abuts against a shoulder t at the upper part of a recess tin-the lever T. A thumb switch '0 is connected to the member if and ifpressed down as the operator pulls the; lever T the switch Thedistributor is shown in.

through the distributor, and therefore through the fuze of the bombbeing released, when the release switch K operates as hereiubeforedescribed.

The connection from the operating lever Q is attached to the arm 6 ofthe lever T and on pulling over the lever T the lever Q, is moved overand displaces the release bar P through one step. If the catch '0 i notpressed down the bomb 'X is released without ignition of the fuze, butif,

the catch 0 has been operated the switch arm V closes the ignitioncircuit and ignition of the fuze takes place on release of the bomb.

While a rack for dropping a succession of bombs has been shown, theignition system is equally applicable to a single bomb release device orto release mechanism for any desired number of bombs. The operatinglever T moreover is not necessarily provided with the electrical switchdevice, as this may if required be separate from the lever andseparately actuated.

What I claim and desire to secure by Letters Patent of the UnitedStates, is

1. In a fuze. for fuzed bodies adapted to be dropped from aircraft whichhave a gripping contact device, a projecting member on the fuze adaptedto be held by said gripping contact device, a timing device providedwith fuze composition, an electrical ignition device adapted to ignitethe said composition, said-projecting member having a pair of electricalcontacts insulated from each other and connected to the electricalignition device.

'2. In a fuze for fuzed bodies adapted to be dropped from aircraft, atiming device provided with fuze composition, an electrical ignitiondevice adapted to ignite the said composition, a projecting head mountedto swivel in the end of the fuze, a pair of external contacts on thehead, which contacts are insulated from each other, and an electricalconnection from one of the said head contacts to the electrical ignitiondevice, the said connection including a rubbing contact surface allowingthe swivelling head to turn .while maintaining the electricalconnection.

3. In a fuze for fuzed bodies adapted to be dropped from aircraft, timerings provided with. fuze composition, an electrical fuze primer adaptedwhen energized to ignite the said composition, a fixed central contactin the fuze body connected to the said primer, a fuze cap, an externalprojecting head mounted to swivel in the said fuze cap, the said headhaving a pair of external contacts insulated from each other, and aspring pressed contact member in the said head connected to one of theinsulated head contacts and adapted to press on the said fixed contact,for the purpose specified.

4. In a fuze as claimed in claim 1 adapted for use with bombs, a strikermounted on the fuze and adapted for impact firing of the bomb, a fixedsupport for the fuze, asafety distance piece interposed between the fuzebody and the fixed support and fuze fired explosive means ignited by thefuze composition at the end of a predetermined delay period, whichexplosive means onoperation blows out the said distance piece and armsthe impact fuze.

5. In a fuze as claimed in claim 1 adapted for use with bombs, a strikermounted on the fuze and adapted for impact firing of the bomb, a fixedsupport for the fuze, a distance piece in the form of two transverselydivided collar members interposed between the fuze body and its fixedsupport, means for holding the two collar members in position, and asmall outwardly driving explosive charge provided for each collar memberand adapted to be ignited by the fuze composition at the end of apredetermined delay period, the said explosive charges driving outwardlythe collar members and arming the impact fuze.

6. In release andelectrical ignition mechanism for fuzed bodies having afuze and provided with a contact carrying head,-

means for. holding and releasing the fuzed body, an extensible releaseswitch adapted to hold the aforesaid fuze contact head, means forclosing the electrical circuit after a predetermined movement of thesaid switch on release of the fuzed body, and

means for releasing the fuze head after. a further movement of the:switch, the ignition circuit being maintained closed until g1:1 releaseof the head, for the purpose speci- 7. A release switch as claimed inclaim 6, provided with a projecting web having a number of perforationsadapted for use in suspending the said switch from the aircraft in anyone of a series of positions.

8. In releaseand electrical ignition mechanism for fuzed bodies havingafuze provided with-a contact carrying head, an extensible releaseswitch comprising spring controlled contact making and gripping jawsadapted to hold the aforesaid fuze con tact head, a telescopic springcontrolledmember carrying the said gripping jaws, a fixed contact, aco-operating movable contact on the telescopic member, ada tedto meetthe fixed contact after an initia movement of the said member, and meansfor opening the gripping jaws automatically after a predeterminedextension of the telescopic member, for the purpose specified.

9. In release and electrical ignition mechanism-- for fuzed bodieshaving a fuze,'provided with a contact carrying head, an operating levereffecting the release of the said fuzed body, an electrical fuze releaseswitch adapted to engage the contacts on the said fuze and an operatingswitch associated with the operating lever and adapted to close part ofan electrical ignition circuit which passes through the said fuzerelease switch.

10. In release and electrical ignition mechanism for fuzed bodies havina fuze provided with a contact carrying head, an operating levereffecting the release of the said fuzed body, an electrical fuze releaseswitch adapted to engage contacts on the said fuze, an electrical switcharm mounted on the said operating lever and provided with a catch whichprevents closing of the switch until the catch is moved into freeposition and an electrical ignition circuit controlled by the saidswitch arm and passing through the said fuze release switch.

11. In a release and electrical ignition system for fuzed bodies adaptedto be dropped from aircraft, means on the aircraft for supporting afuzed body, means for releasing the said body at will, an independentattachment on the aircraft fol the fuze of the said body, an electricalignition circuit adapted to be completed through the said fu zeconnection, and means for completing the circuit only after apredetermined movement of the fuzed body subsequent to its release.

12. In a release and electrical ignition system for fuzed bodies adaptedto be dropped from aircraft, an aircraft rack provided with means forsupporting the said fuzed bodies and for releasing them in successionand with separate detachable connecting means for the fuzes of the saidbodies, an electrical ignition circuit on the aircraft adapted to becompleted through the said fuze connecting means, and means forcompleting the circuit through a fuze connection only after apredetermined movement of afuzed body subsequent to its release.

13. In a release and electrical ignition system for fuzed bodies adaptedto be dropped from aircraft, an aircraft rack adapted to release insuccession a number of fuzed dropping bodies, a fuze release switch foreach fuze with which it is adapted to engage, a series of electricalfiring circuits connected up through the said release switches and adistributor switch on the rack adapted to close the said electrical fir-.ing circuits in succession at successive operswitches, a distributorswitch provided with a series of contacts each in one of the aforesaidfiring circuits, a sliding member on the rack moved step by step at therelease of successive fuzed bodies and a contact maker on the saidsliding member adapted to make contact successively with the contacts ofthe distributor switch immediately before the corresponding fuzed bodiesare released.

15. In a release and electrical ignition system for fuzed bodies adaptedto be dropped from aircraft, an aircraft rack comprising a supportingframe, means for detachably securing a series of fuzed dropping bodies,a sliding release bar adapted to release the said bodies from theirsecuring means in succession, means for moving the release bar step bystep, a series of supporting brackets corresponding in number to thedropping bodies, a source of electrical cur rent on the aircraft, aseries'ofelectrical release switches suspended from the aforesaldsupporting brackets and adapted for electrical connection to the fuzesof the dropping bodies, and means operated b the aforesaid slidingrelease bar for comp etmg a circuit through the release switches insuocession.

OWEN DAVID LUCAS.

